How long do eclipses last

ET on Monday, will cross the U. The once-in-a-lifetime event on Aug. The path of totality, which starts in Oregon and ends in South Carolina, is about 70 miles wide. Total solar eclipses can be seen when the moon passes directly between the sun and the Earth and the moon completely covers the entire face of the sun.

Skygazers in Lincoln Beach, Ore. A partial eclipse begins there at a. PST and totality starts at a. For a solar eclipse to occur, the New Moon must be at or very close to one of the two points where the orbital planes meet.

These locations are called lunar nodes. If the Moon is not near a lunar node during New Moon, the Sun, Moon, and Earth do not align in a straight or almost straight line, and a solar eclipse cannot occur. Seen from Earth, the Moon passes just above or just below the Sun see image.

The Moon's path around Earth is elliptical, with one side of the orbit closer to Earth than the other. The point closest to Earth is called the perigee and the side farthest from Earth is known as the apogee.

Earth's orbit around the Sun is also elliptical, with the Sun closest at perihelion , and farthest away at aphelion. It also means that from Earth, the Sun's and Moon's apparent sizes change during the year. When the Moon is about times closer to Earth than the Sun, the Moon's and the Sun's apparent sizes roughly match. Because of this, total eclipses of the Sun can only occur when the Moon is near perigee—it is the only time when the disk of the Moon looks big enough to cover the entire disk of the Sun.

What if the Moon is near apogee? A total solar eclipse can last for several hours and totality can range from a few seconds to 7. The longest total solar eclipse of the 21st century took place on July 22, , when totality lasted 6 minutes and 39 seconds!

More details about upcoming Eclipses. Two observers are indicated, observer 1 is closer to the edge of the path and observer 2 is at the centerline.

This page requires JavaScript to be enabled in order to function properly. It appears it is currently turned off for your browser. Western Kentucky University. Apply Visit More Info.